Window Experts TwinSash Windows are designed to provide ultimate flexibility for fabricators and clients alike. It provides the option of combining the traditional casement window with traditional inward opening fly screen option. There is a facility to incorporate a security grill or blinds for security or privacy. It also offers an additional variant of sash with integrated louvers with fly screen option. It was designed to facilitate maximum application coverage with the minimum number of profile sections providing fabricator and at the same time the end user with the ideal range of products.